Supercharger for internalcombustion engines



Oct. 24, 1944, c. K. NEWCOMBE 7 2,360,969

SUPERCHARGER FOR INTERNAL-COMBUSTION ENGINES Filed Jan. 3. 1942 vapour being used Patented Oct. 24, 1944 SUPERCHARGER FOR INTERNAL,-

GOIWBUSTION ENGINES Clare Kenzie Newcombe, Manchester, England,

assignor to Heat Pumps land, a British company Limited, London, Eng- Application January 3, 1942, Serial No. 425,558 In Great Britain December 9, 1940 3 Claims.

This invention is for improvementsin or relating to superchargers for internal-combustion engines, particularly aircraft engines.

It has already been proposed to drive an aircraft engine supercharger by means of a turbine fed with exhaust gases from the aircraft engine. With this method, there arises the disadvantage not only that the turbine is subjected to the corrosive effect of the exhaust gases, which in a modern aircraft engine reach high temperatures, but also that the back pressure in the exhaust system may adversely afiect the running of the aircraft engine. In addition, the pressure 1 of the gas in the turbine cannot be regulated, to

any considerable extent, without aflecting the performance of the "engine. For the latter two reasons, it has not hitherto been possible to employ this known form of supercharger drive for an aircraft engine of the two -stroke type'with any degree of success.

This invention is concerned with another a known method of driving a turbine-operated supercharger of an internal-combustion engine in which pressure vapour developed at least in part by the liquid cooling system of the engine is supplied as the motive power for the turbine. In carrying out a method of this type, various proposals have been made; for example, it has beensuggested that the liquid cooling system or the engineshould be arranged to act as a preheater for a cooling liquid to be subsequently vaporized in an exhaust-gas heated boiler, the to drive a turbine blower for the engine.

In carrying out the method of the above kind and according to the present invention an in- Jectnr-typeheat pump is employed for raising the temperature and pressure level of the vapour generated by the cooling system. Thus the invention provides, in an internal-combustion engine, the combination of a turbine-driven supercharger for the engine, an engine cooling system employed as the cooling medium, a liquid having e physical characteristics of the working fluid of a refrigerating plant, and--- an injector-type heat pump arranged to boost the temperature and pressure level of the vapour generated by the cooling system and to supply that vapour as motive power for driving the supercharger turbine.

Any of. the fluid refrigerant media that arecommonly employed in refrigerating apparatus comprising evaporative elements of the s0.-ca1led flooded type may be employed as'the cooling medium in the apparatus of the present invention, it being necessary 'to select a substance which, under operating conditions, will, on the one hand, maintain the engine cylinders below a selected temperature value and, on the other hand, will, by virtue of the heat absorbed from the engine, produce vapour under a pressure suflicient to provide the necessary energy for driving the turbine of the supercharger. The pooling medium is preferably one of the Freon group such as Freon 12 or dichlorodifluoro-methane which is non-toxic, has little or no action upon metal and can be useful for its fire-extinguishing properties in the event of a crash. However, other known refrigerant liquids can also be'employed, for example methyl bromide which, although it is toxic, has the advantage of high molecular weight and I therefore enables the superchargen turbine to be of small dimensions, and also carbon tetrachloride.

One example according to the invention will now be described with reference to the accom-.

thereof. The inlet pipe 4 feeds from a liquid circulating pump 6 of any suitable type. Preferably,

. the engine cylinder formsbut a preheater for I the cooling medium, a boiler proper being formed in the liquid outlet pipe bycoiling a pipe 2! at 6 around the exhaust manifold I. From the boiler, the mixture of liquid and vapour passes into a vapour injector type heat pump 20 from which vapour of. energy content increased by said pump 20 is supplied to the turbine 9, the exhaust being passed into a condenser Ill, e.'g., of the j radiator type, thence to the pump.

The exhaust timing ofthe engine may be so altered that the major portion of the energy is contained in the exhaust gases; this energy would be transferred to the pressure vapour and the turbo-unit would develop the greater portion of the efiective.horse-power. v

It"-. will be seen that the exhaust-gas heated boiler is, used to generate pressure vapour whichin turn is utilized as the motive power of the iniector-type heat pump 20 for raising the temperature level of thevapour generatedby the bine by increasing the pressure of the cooling vapour.

I claim:

level oi the vapour generated by the cooling system and to supply that vapour as motive power for driving the supercharger turbine, an exhaust- 1. In an internal-combustion engine, the com,- bination of a turbine-driven supercharger for the engine, an engine cooling system employing as the cooling medium a liquid having the physical char acteristics of the working fluid of a refrigerating plant, an injector-type heat pump arranged to boost the temperature and'pressure level of the vapour generated by the cooling system and to supply that vapour as motivepower for driving the supercharger turbine, .ian'd an exhaust-gas heated boiler arranged to generate the pressure vapour used as motive power for the heat pump.

2. In an internal-combustion engine, the combination of a turbine-driven supercharger for the engine, an engine cooling system employing as the cooling medium a liquid having the physical characteristics of the working fluid of a refrigerating plant, an injector-type heat pump arranged to boost the temperature and pressure gas heated boiler arranged togenerate the pressure vapour used as motive power for the heat pump, and a circulating pump for the cooling 7 liquid.

3. In an internal-combustion engine, the combination of a turbine-driven supercharger for the engine, an engine cooling system employing as the cooling medium a liquid having the physical characteristics oi the working fluid of a refrigerating plant, an injector-type heat pump arranged to pump.

CLARE KENZIE NEWCOMZBE. 

